Hi all, used Wickes liquid DPM which is actually quite nice to use. Once dry I want to apply latex levelling compound but have been told I'll need to prime the DPM. Is this really necessary? If so what should I use? Stopgap P131 Neoprene primer or just PVA? I have to apply a second coat tomorrow and was thinking of dusting with Dried sand, would that overcome the need for specialist primer?

Thanks

ps laying limestone once finished incase that has any bearing.